Two-dimensional layered semiconductor/graphene heterostructures for solar photovoltaic applications

Schottky barriers formed by graphene (monolayer, bilayer, and multilayer) on 2D layered semiconductor tungsten disulfide (WS 2 ) nanosheets are explored for solar energy harvesting. The characteristics of the graphene-WS 2 Schottky junction vary significantly with the number of graphene layers on WS 2 , resulting in differences in solar cell performance. Compared with monolayer or stacked bilayer graphene, multilayer graphene helps in achieving improved solar cell performance due to superior electrical conductivity. The all-layered-material Schottky barrier solar cell employing WS 2 as a photoactive semiconductor exhibits efficient photon absorption in the visible spectral range, yielding 3.3% photoelectric conversion efficiency with multilayer graphene as the Schottky contact. Carrier transport at the graphene/WS 2 interface and the interfacial recombination process in the Schottky barrier solar cells are examined. Schottky barriers formed by graphene (monolayer, bilayer, and multilayer) on 2D layered semiconductor tungsten disulfide (WS 2 ) nanosheets are explored for solar energy harvesting.